STRUCTURE OF YIELD OF CORN HYBRIDS DEPENDING ON ELEMENTS OF AGROTECHNOLOGY

Abstract

The purpose. Improvement of agrotechnical measures of the technology of growing new domestic hybrids of corn in the conditions of the Central Forest-Steppe of Ukraine, including the determination of indicators of the structure of the cob, which affect the productivity of plants of corn hybrids of different FAO groups. Methods. Two-factor field experiment, methods of mathematical statistics. Results. The current direction of modern agricultural production is the cultivation of corn hybrids of various FAO groups, which are adapted to the soil and climatic conditions of a certain zone of Ukraine. The object of research was the formation of the yield structure in newly created domestic hybrids: Zedan 26 (FAO 240), Zedan 26 (FAO 240) and Zedan 28 (FAO 260). Among corn hybrids, the average number of grains in a row was 38.9 pcs. in the Zedan 26 hybrid, 41.9 pcs. in the Zedan 28 hybrid, and 44.9 pcs. in the Zedan 32 hybrid. The maximum indicators of the number of grains in a row of a corn cob are from 42.3 to 48.4 pcs. was on plant density variants of 70 thousand plants/ha. The maximum value of the cob length was noted in the hybrid Zedan 32 – 18.8 cm. The maximum value of the cob length was observed at a plant density of 70 thousand plants/ha from 17.3 to 19.0 cm. The largest seeded cob length (on average by density) is characterized by the mid-ripe hybrid Zedan 32 (18.2 cm). The indicator of the diameter of the cobs of hybrids under the influence of plant density varied unevenly, but there was a tendency to increase its size at a plant density of 70,000 plants/ha by 0.6–1.5 cm compared to a density of 100,000 plants/ha. An important feature of corn grain productivity is the mass of grain from the cob. The most favorable conditions for the growth and development of plants, and as a result, the formation of the maximum indicators of the mass of grain from the cob in the experiment were formed on the variant with a density of 70 thousand plants/ha and were, respectively, 153.8 g in Zedan 26, 169.7 - in Zedan 28, 202.9 g in Zedan 32. It was established that the length of the seeded cob is positively correlated at a high level of significance in the hybrid Zedan 32. The correlation coefficient was 0.711, which indicates the possibility of increasing grain yield by increasing the seeding of the cob. In the Zedan 26 hybrid, the highest yield is predicted for the cob length of 16.9–17.9 cm. In the Zedan 28 hybrid, the maximum manifestation of grain yield is recorded for the seeded cob length in the range of 16.0–16.5 cm. The set parameters of the cob structure indicators, which affect the productivity of corn hybrid plants of different FAO groups (240–320) and intensity, for varying the density of the cenosis from 70 to 100 thousand plants per hectare of sowing. Conclusions. It was established that the studied elements of the structure of the productivity of the cob depended on the genotype of the hybrid and variants of the growing technology, and to realize the genotypic potential, it is necessary to establish an individual reaction to technological measures. The Zedan 32 intensive type corn hybrid had a high linear correlation of grain yield and cob weight (r=0.635). However, the maximum yield was at the level of 170–190 g of grain from a cob. An increase in the mass of cob grain above these parameters predicted a decrease in crop productivity. The conflict between the individual productivity of the plant and the productivity of the crop was caused by the density of the cenosis, which requires the establishment of the optimum density of plants in the crop through experimentation. Maize hybrids Zedan 28 and Zedan 26 had certain limitations of individual plant productivity to realize potential crop productivity. An increase in the mass of grain from a cob over 160 g can lead to a sharp drop in grain yield. In these hybrids, increasing the mass of grain from the cob by agrotechnical measures (due to a decrease in plant density) leads to a sharp decrease in grain yield. The peculiarity of these hybrids is the genotypic component, which allows their cultivation at a high density of cenosis. To obtain the maximum yield of each hybrid in the conditions of the Central Steppe of Ukraine, it is necessary to take into account the peculiarities of their reaction to the density of the sowing cenosis.